The subject invention relates to autogenous blood pumping devices which replace or assist a heart in pumping blood. Since the material used in the construction of the heart/assist is derived mainly from native tissue, problems with immunorejection are minimized.
There are approximately 250,000 new cases of cardiomyopathy in the United States yearly. Five year survival of these cases is approximately 25%. Because of insufficient number of homologous heart donors, a new heart source is needed. The subject invention provides autogenous heart suitable for this group of patients.
A series of patents to Pierre-Andre Grandjean (U.S. Pat. Nos. 5,069,680, 5,089,019, 5,098,442, issued Dec. 3, 1991, Feb. 18, 1992 and Mar. 24, 1992, respectively, the contents of which are herein incorporated by reference), describe muscle stimulators and apparatuses and methods for their control. The Grandjean patents deal with skeletal muscle use in a cardiac assist system. As described by Grandjean, cardiac muscle can be used in direct circumscription of a human heart to assist the heart in contracting. Alternatively, the heart assist can be an artificial chamber which is inserted in series within the descending aorta or distally connected to a major artery.
U.S. Pat. No. 5,007,927, issued Apr. 16, 1991 to Badylak, et al. teaches a muscle-powered cardiac assist device (the contents of this patent are herein incorporated by reference). This cardiac assist device is formed from rectus abdominis muscle and latissimus dorsi muscle in which the skeletal muscle has been modified to decrease fatigue through the use of electrical stimuli, which promotes conversion of fast twitch muscle fibers into slow twitch muscle fibers. As is known, slow twitch muscle fiber has a greater tolerance for long term contractile loading.
U.S. Pat. No. 4,411,268, issued Oct. 25, 1983 to Cox, teaches a muscle stimulator useful for inducing a functional contraction in muscle tissue while conditioning the contractile properties of that tissue (the contents of this patent are herein incorporated by reference).
The subject invention provides an autogenous four-chamber heart which is meant as an alternative to heart transplants and the mechanized replacement hearts currently used when the native heart is unable to function and provides the following advantages: Immunoreaction and possible rejection are essentially eliminated since the materials employed are autogenous. No heart donor is required, eliminating the tissue matching and waiting process. A "spare heart" can augment a deficient native heart while retaining benefits provided by the native heart.
The subject invention also provides an autogenous cardiac assist device which is meant to supplement a deficient heart and provides the following advantages: Immunoreaction and possible rejection are essentially eliminated. No donor is required. Placement can be proximate or distant to the heart. Multiple assists can be employed in a single patient. A single opening permits greater muscle circumscription of the chamber.